Automatic document feeder having a document-ejecting/feeding mechanism

ABSTRACT

A document-ejecting/feeding mechanism is assembled inside an automatic document feeder, includes a driving device, gears, one-way clutches and rollers. After feeding action is canceled, the driving device is reversed and cooperates with the action of gears and one-way clutches, and at least one of rollers that near the paper-ejecting position is still rolled to the paper ejecting direction. Therefore, after the feeding action is canceled, the document will be still moved out from the feeder automatically and not tore.

FIELD OF THE INVENTION

[0001] The present invention relates to a document-ejecting/feeding mechanism. The mechanism is used with an automatic document feeder of an image input/output device. The documents that are not ejected from the feeder can be released after canceling the document feeding function.

BACKGROUND OF THE INVENTION

[0002] The automatic document feeder is usually cooperated with image input/output device and feeds one document at a time in the image input/output device. Taken an assembly of a scanner and an automatic document feeder as an example, each sheet of a pile of documents on the automatic document feeder can be fed to the scanning zone of the scanner to proceed scanning and obtaining images.

[0003] In order to save time of the gaps during each feed, the documents are sent one by one in the feeder and a specific gap is defined between two adjacent documents so that there are two documents in the feeding path at a time.

[0004] When the rear end of the first document is scanned, it is expected that the front end of the second document is located at the beginning position in the scanning zone. The first document is sent out from the feeder while the second document begins to be scanned.

[0005] If the scanning action is canceled during the feeding of the documents (this canceling can be done by programmed software of computers), the documents in the scanning path are not yet scanned can be taken out by opening the cover of the feeder.

[0006] However, the document that has been completely scanned is remained in the feeding path and stocked between rollers. The document may be pulled out by rotating the rollers or pulling the document directly. The rollers are engaged with gears which transmit power from the motor, so the pulling of the document rotates the motor. The damping force of the motor is magnified by the reduction gears so that the document could be torn when being pulled.

[0007] When a user wants to scan a pile of documents, either he/she can use a scanner to scan the whole pile of documents by using an automatic document feeder at a time, or he/she can use a scanner to scan one document by using the feeder to send one document at a time.

[0008] The inherent problems of continuous feeding of the automatic document feeder have been mentioned hereinbefore. It will depict the inconvenience when using the automatic document feeder to send the document one by one hereinafter.

[0009] Due to the fact that two documents are located in the feeding path at the same time, the first document cannot be released even if it is completely scanned, and this will blockade the process of the scanning action. Besides, the users perhaps thought that the scanner does not work in order. Besides, when the first document after being scanned has to be taken to another place immediately, the first document still in the scanner and cannot be easily taken out. The conventional feeders cannot provide a solution for these problems.

SUMMARY OF THE INVENTION

[0010] The primary object of the present invention is to provide a document-ejecting/feeding mechanism, and in particular to automatically send the document out from the feeder when the feeding order is canceled.

[0011] The purpose is achieved by reversing the driving device cooperated with gears and one-way clutches to let at least one roller keep rolling to send the document out. Therefore, even if the feeding order is canceled, the document can be sent out.

[0012] The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, preferred embodiments in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a cross sectional view to show the automatic document feeder of the present invention.

[0014]FIG. 2 is a perspective view to show the ejecting/feeding mechanism of the feeder of the present invention.

[0015]FIG. 3 is a side view to show the ejecting/feeding mechanism of the feeder of the present invention.

[0016]FIG. 4 is another side view to show the ejecting/feeding mechanism of the feeder of the present invention.

[0017]FIG. 5 shows the feed of documents of the present invention.

[0018]FIG. 6 shows the ejection of documents of the present invention.

[0019]FIG. 7 shows the first status of the concise version of the present invention.

[0020]FIG. 8 shows the second status of the concise version of the present invention.

[0021]FIG. 9 shows the third status of the concise version of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022]FIG. 1 shows the automatic document feeder which has a body 10 with a document-ejecting/feeding mechanism 20 received therein.

[0023] The body 10 has an input end 11 and an output end 12, wherein a U-shaped passage 13 is connected between the input end 11 and the output end 12. A plate 14 is located on a side of the input end 11 so that documents (not shown) are put on the plate 14. A scanning zone “S” is defined as the zone for scanning the document.

[0024]FIG. 2 shows the document-ejecting/feeding mechanism 20 which has a plurality of rollers 21, 22, 23, 24, a set of driving device 31, a plurality of one-way clutches 41, 42.

[0025] The feeding roller 21 is mounted on a shaft 25 whose first end 251 and second end 252 are respectively connected with the one-way clutches 41, 42. The one-way clutch 42 on the second end 252 has a pulley 253 connected thereto.

[0026] In this embodiment, the number of ejecting rollers 24 is two (the number also may be one or more than two) and are mounted on a shaft 28 whose first end 281 and second end 282 are respectively connected to a one-way clutch 41 and a pulley 283. The one-way clutch 41 has a gear 43 connected thereto and is installed in a direction opposite to the direction of the one-way clutch 42.

[0027] In this embodiment, the number of assist rollers 22 is two (the number may be one or more than two) and the rollers 22 are mounted on a shaft 26 which has a first end 261 and a second end 262 which is connected to a pulley 264. The assist rollers 22 are located between the feeding roller 21 and the ejecting roller 24.

[0028] The number of assist rollers 23 is two and the two assist rollers 23 are mounted on a shaft 27 which has a first end 271 and second end 272 which is connected to a pulley 273. The assist rollers 23 are located between the assist rollers 22 and the ejecting rollers 24.

[0029] The driving device 31 includes a motor (not shown), a plurality of transmission pulleys 32, 33, 34, and 35, and a plurality of belts 36, 37, 38 and 39.

[0030] The output shaft (not shown) of the motor is connected to the transmission pulley 32 which is connected to another transmission pulley 33 by a belt 36. Another transmission pulley 331 is co-axially connected to the transmission pulley 33.

[0031] Referring to FIGS. 2 and 3, the transmission pulleys 331, 34, 35 and the one-way clutch 41 which is also a transmission pulley on the first end 251 of the shaft 25 form four points of a quadrilateral with the belt 37 winding around the four points.

[0032] It is to be noted that the transmission pulley 34 is an idle gear for changing the transmission direction of the output from the belt 37. A gear 341 co-axially connected to a side of the transmission pulley 34 is engaged with the gear 43 on a side of the one-way clutch 41.

[0033] The transmission pulley 35 has a co-axially connected gear 351 which is engaged with the gear 53 on the shaft 52 of the feeding roller 51.

[0034] Referring to FIGS. 2 and 4, the belt 38 is wound around the pulleys 253 and 264, and the belt 39 is wound around the one-way clutch 42 on the second end of the shaft 25 and the pulleys 273, 283.

[0035] As shown in FIG. 1, the ejecting/feeding mechanism 20 is located between the input end 11 and the output end 12 of the body 10. The feeding roller 21 is located close to the input end 11, and the ejecting roller 24 is located close to the output end 12. Each of the feeding roller 21, the assist rollers 22, 23 and the ejecting roller 24 has a part located in the passage 13.

[0036]FIG. 5 shows the feeding action, wherein the scanned document is released from the scanning zone and the next document has not yet entered in the scanning zone “S”. When the motor (not shown) rotates clockwise, the transmission pulleys 331, 34, 35 and the one-way clutch 41 are rotated clockwise. The gear 351 connected with the transmission pulley 35 is engaged with the gear 53 so as to drive the feeding roller 51 to feed the document 61 into the mechanism 20 via the passage 13 which is not shown.

[0037] The feeding roller 21 and the assist roller 22 are connected by the belt 38 so that the feeding roller 21 and the assist roller 22 have the same rotational direction.

[0038] The feeding roller 21 and the assist roller 23 are connected by the belt 39 so that the feeding roller 21 and the assist roller 23 have the same rotational direction.

[0039] It is to be noted that the ejecting roller 24 includes a one-way clutch 41 on an end thereof and the gear 43 cooperated with the one-way clutch 41 is engaged with the gear 341 mounted to the transmission pulley 34. When the gear 341 is rotated clockwise, the gear 43 rotates in opposite direction so that the one-way clutch 41 is in idle status.

[0040] The pulley 283 on the other end of the ejecting roller 24 is connected to the feeding roller 21 by the pulley 39, so the ejecting roller 24 is rotated in the same direction as the feeding roller 21.

[0041] The documents 61 can be released after being transported by the same rotational direction of the feeding roller 21, the assist rollers 22, 23 and the ejecting roller 24.

[0042]FIG. 6 shows the ejection of document. When the feeding order is canceled which can be achieved by software, the motor (not shown) rotates in reverse (counterclockwise). The transmission pulleys 331, 34, 35 and the one-way clutch 41 are rotated counterclockwise.

[0043] Because the one-way clutch (not shown) connected to the shaft 52 of the ejecting roller 51 is not used, the gears 351, 53 will not let the feeding roller 51 feed the documents in the document-ejecting/feeding mechanism 20.

[0044] Because each of two ends of the feeding roller 21 includes a one-way clutch 41/42 which is in idle status, the feeding roller 21 does not rotate.

[0045] The assist roller 22 and the feeding roller 21 is driven by the belt 38 and the assist roller 22 is not connected with other rollers so that when the feeding roller 21 is in idle status, the assist roller 22 does not rotate.

[0046] The gear 341 of the transmission pulley 34 is engaged with the gear 43 of the ejecting roller 24, so that when the gear 341 is rotated in counterclockwise, the gear 43 is rotated clockwise. The one-way clutch 41 is operated to let the ejecting roller 24 rotate clockwise.

[0047] Although the ejecting roller 24, the assist roller 23 and the feeding roller 21 are connected by the belt 39, the one-way clutch 42 on the feeding roller 21 is in idle status and the assist roller 23 is driven by the ejecting roller 24 only. So, the feeding roller 21 is remained in still and the assist roller 23 and the ejecting roller 24 are rotated clockwise. By this way, the document 61 located at the bottom of the assist roller 23 and the ejecting roller 24 may be automatically ejected.

[0048] Therefore, when ejecting the document, the motor rotates counterclockwise and the roller on the left side of the scanning zone “S” keeps on rotating in the original direction, and the roller on the right side of the scanning zone “S” is remained in still. The document that escaped from the scanning zone “S” is ejected by the document-ejecting/feeding mechanism 20.

[0049] FIGS. 7 to 9 show a concise version of the present invention, which needs only two feeding rollers, rather than four feeding rollers. In comparison with FIG. 2, the assist rollers and related parts are saved.

[0050] Referring to FIG. 7, the motor is rotated clockwise to drive the pulley 32 counterclockwise. The belt 36, the transmission pulleys 33, 331, the belt 37, the transmission pulley 34, the gear 341, the transmission pulley 35, and the one-way clutch 41 are rotated counterclockwise. The one-way clutch 41 on the first end 251 of the shaft 25 drives the shaft 25 and the feeding roller 21. The shaft 25 also drives the one-way clutch 42 on the second end 252 of the shaft 25, belt 39, the pulley 283 on the second end 282 of the shaft 28, the shaft 28 and the final ejecting roller 24 in counterclockwise. On the hand, the gear 341 drives the gear 43 on the first end 281 of the shaft 28 and the one-way clutch 41 clockwise. The one-way clutch 41 is not activated so as to allow the directions of the shaft 28 and the gear 43 to be different. By this way, the feeding may work normally.

[0051] Referring to FIG. 8, when ejecting the document, the motor is rotated in reverse and the pulley 32 rotates clockwise. The belt 36, the transmission pulleys 33, 331, the belt 37, the transmission pulley 34,-the gear 341, the transmission pulley 35 and the one-way clutch 41 are rotated clockwise. The one-way clutch 41 does not function so that the shaft 25 and the feeding roller 21 are not rotated. On the other hand, the gear 341 drives the gear 43 and the one-way clutch 41 counterclockwise. The one-way clutch 41 drives the shaft 28 and the final ejecting roller 24 counterclockwise. The shaft 28 drives the pulley 283, the belt 39 and the one-way clutch 42 to rotate counterclockwise. At this presence, the one-way clutch 42 is not activated so that the shaft 25 is remained in still.

[0052] Therefore, the final ejecting roller 24 rotates clockwise whichever direction the motor is rotated.

[0053] As shown in FIG. 9, as long as the feeding roller 21 and the ejecting roller 24 are located on two sides of the scanning zone “S”, the above mentioned functions of the ejecting/feeding function can be achieved.

[0054] The roller located close to the output end is remained in its original rotational direction to eject the document by reversing the motor and the cooperation of the gear and the one-way clutch even if the feeding order is canceled during scanning process. The last document can be ejected without the need of pulling manually.

[0055] Furthermore, by using the feeder of the present invention, the user may scan one document at a time and no document will be trapped in the feeder.

[0056] While we have shown and described the embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

What is claimed is:
 1. An automatic document feeder, comprising: a body having an input end from which a document is input and an output end from which the document is output; a document ejecting/feeding mechanism located in the body and between the input end and the output end, and having a plurality of rollers and a driving device for driving the rollers, wherein at least one of the plurality of rollers located close to the output end is rotated in an output direction for outputting the document away from the output end when the driving device rotates clockwise, and in the output direction when the driving device rotates counterclockwise.
 2. The automatic document feeder as claimed in claim 1, further comprising a scanning zone at which the document is scanned, and the rollers includes a feeding roller located at a side of the scanning zone and an ejecting roller located at the other side of the scanning zone.
 3. The automatic document feeder as claimed in claim 2, further comprising a first one-way clutch and a second one-way clutch connected to two ends of the feeding roller, respectively, and two respective operation directions of the first one-way clutch and the second one-way clutch being opposite to each other.
 4. The automatic document feeder as claimed in claim 3, further comprising a third one-way clutch connected to at least one end of the ejecting roller, and an operation direction of the third one-way clutch being the same as that of one of the first one-way clutch and the second one-way clutch.
 5. The automatic document feeder as claimed in claim 2, further comprising at least one assist roller which assists the feeding roller to feed the document and the ejecting roller to eject the document.
 6. The automatic document feeder as claimed in claim 1, wherein the driving device includes transmission pulleys and belts. 